Subsonic does not allow us to see subtitles in .MKV. In my opinion a change to this would benefit more people then making a simple changes to playlist features etc.
Having the option to stream all my .mkv files and have the subtitles available to my android phone would be awesome.
There is a thread where some people posted a possible way to enable this in Ubuntu but it would be great to get a fix for us non programming people.
I know if this was enabled I would increase my donation to the project

On a side note OGM files do not play subtitles either but it is not super important because I only have one series in .OGM